This invention relates to a roof or wall structure comprising oblong plates having lateral edge portions in the form of partially open cylindrical resilient flanges and in which a flange of one plate is snap locked over a flange of an adjacent plate.
Such roof or wall structures are described in the specification of British Pat. No. 1,078,792.
As described in the above patent specification a structure, e.g. a roof structure, of the above mentioned type is ordinarily fastened to a support with fastening means comprising a flat head portion having a contour corresponding to the shape of the interior of the inner flange of a set of interconnected flanges and a fastening portion, e.g. having a hole for attaching said portion of the fastening means to a support by means of a nail or a screw.
In case the support is a rafter and lath construction, the rafters should be provided with a spacing of about 60 cm to make the construction stable. However, such wooden constructions are relatively expensive and have a heavy and clumsy appearance.
When using the above mentioned fastening means, the flat head portion thereof is introduced into the interior of the inner flange of a pair of interlocked flanges and is placed perpendicular to the longitudinal axes of said flange. It is then fixed in this position by attaching the fastening portion to the support, such as a rafter or a lath. The fastening means ordinarily have to be mounted at intervals of about 60 cm in order to make the roof structure resistant against wind forces.
The object of the invention is to eliminate or reduce the above mentioned drawbacks of the prior art roof or wall structures.